An aircraft door consists essentially of an outer skin, which in the closed state of the aircraft door is matched to the surface contour of the fuselage, and also a rear body structure, which is connected with the outer skin and gives the latter the necessary rigidity. This structure is also provided for doors designed as hatches, which are arranged without hinge units in a frame fitted to the fuselage, and are closed in normal operation of the aircraft, so that for reasons of simplification the term aircraft door or door also includes hatches of this type, in particular emergency evacuation hatches and access hatches, which enable an emergency evacuation or provide access for maintenance tasks.
Emergency evacuation hatches are inserted into the frame from the interior and are locked by means of a locking mechanism. In an emergency situation the hatch can be unlocked and lifted out of the frame into the interior of the aircraft; it is then thrown sideways out of the aircraft through the opening created so as to clear an emergency route, onto the wing, for example. A window ensures that the operator can detect any risks outside the aircraft fuselage, such as fire, obstacles, and similar, and if necessary leaves the hatch closed.
At the present time it is usual to manufacture aircraft doors of this type in a differential form of construction by means of a riveting and/or adhesive technique with a multiplicity of differing production steps. One production step includes the manufacture of the rear body structure, wherein beam and frame elements are joined together by means of overlaps and ancillary brackets to create a framework. In a method of known art the outer skin, designed as a skin panel, is subsequently connected with the rear body structure, in particular by means of riveting. Here the production resource requirement is significant, since for the manufacture of the rear body structure a large number of individual components and connecting elements is required. Also it is disadvantageous that overlaps and ancillary brackets are necessary for the joining of the individual components in the connecting regions. In addition to high assembly costs this requires an increased structural weight overall.
In addition to the differential form of construction it is furthermore of known art, to manufacture aircraft doors in a single piece, integral form of construction by means of a casting and/or milling technique. From DE 100 46 004 A1 an aircraft door is of known art in which the rear body structure and outer skin are designed in one piece using a sand casting method. This solution has, however, the disadvantage that the moulding tools required have a complex structure and the outer skin can only be cast with a high minimum thickness, so that the door of this type either has a high structural weight or by virtue of the finish machining of the skin field using milling technology is extremely resource intensive in production engineering terms.